Patent Literature 1 describes a centrifugal multiblade blower such as sirocco fan or turbo fan. The blower is equipped with an electric motor and an impeller rotated by the electric motor to blow off air outward in a radial direction.
The impeller has plural blades arranged around a rotation shaft of the electric motor, and a main plate holding the blades and transmitting the rotation power generated by the electric motor to the blades. The main plate has a main part in which plural penetration holes are arranged in the circumferential direction, and a blockade part closing the penetration holes. In the blower of Patent Literature 1, noise resulting from the penetration hole of the main plate is restricted, and water is prevented from entering the electric motor through the penetration hole of the main plate.